Synergic estimation of columnar integrated aerosol properties and their vertical resolved profiles in respect to the scenarios of dust intrusions over Granada

Abstract

In this paper, we present a study of the columnar and vertically resolved aerosol optical properties over Granada (Spain) during dust events detected during July-August in the period 2012e2013. For this purpose, we classified the events according to their origins and pathways. The analyzed aerosol prop- erties include; columnar aerosol optical properties like aerosol optical depth (AOD) and Angstrom exponent (AE), as well as the lidar products, like backscatter-related Angstrom exponent and linear particle depolarization ratio (LDPR). The lidar profiles are used for determination of the geometrical structure of dust layers and the aerosol optical parameters inside dust layers. There are identified 58 dusty days over Granada during the periods July-August, 2012e2013. In 71% of the dust, event analyzed the dust plume over Granada is located between 3000 and 4000 m a.g.l. Mean values of AOD500 according to the Atlantic and Mediterranean pathway were 0.28 ± 0.10 and 0.93 ± 0.17. Meanwhile, the mean values of AE440-870 were 0.57 ± 0.25 and 0.43 ± 0.20. Three region are identified as the main dust sources affecting the dust intrusions over Granada. Two principal pathways of air masses during dust intrusion over Granada were observed: through Atlantic (52.7%) and through Mediterranean (47.3%). Air masses which come through the Mediterranean present larger AOD and lower Angstrom exponent values than those air masses coming through Atlantic. Lidar measurements show different vertical distributions on particle backscatter coefficient, during different scenarios of dust intrusions. The lidar profiles indicate that average base and top heights of all dust during the investigation period were 2.1 ± 0.7 and 4.8 ± 0.9 km, and their center of mass and thickness were 3.3 ± 0.7 and 2.8 ± 1.0 km a.g.l. The AE355/532 profiles for the dust intrusions present some differences depending on the source regions and path followed by the dust. On the other hand, the profiles of LPDRat 532 nm were more similar for all scenarios.